EOS - How to understand license agreement of Linux kernel derivative?

Question

EOS (the industry-leading, Linux-based network operating system) runs across the entire portfolio of Arista’s network switches as well as in a virtual machine instance (vEOS).

EOS operating system being one customisation of Linux kernel used for commercial reasons, I would like to understand the license aspect of EOS (Linux derivative) in terms of,

• Installation rights
• Customisation rights
• Distribution rights
• Support

as commercial product.

Here is EOS distribution model.

Arista also distributes open source EOS that can run on hardware other than Arista switches.

Linux kernel is under GPLv2 distribution model.

This code shows that any new linux kernel module has to include

MODULE_AUTHOR("TEAM XYZ");
MODULE_DESCRIPTION("FIRST MODULE");
MODULE_LICENSE("GPL"); /* This line */

---

Questions:

1) Which party hold the responsibility to support/resolve the bugs of Linux kernel when EOS is in production?

2) Does Arista (vendor) suppose to distribute EOS (commercial product) with source code or as closed source?

3) What is the significance to mention MODULE_LICENSE("GPL") in every Linux kernel module?

Answer 1

1) Who did you buy a support contract from?

2) If they are using GPL software (ie, the Linux kernel) then they must give you the source if you ask for it, and there should be an offer made for it in your documentation, etc. HOWEVER... they may be using binary blobs to keep some things proprietary....

3) This is Linus' policy for submissions made to the main kernel tree. Should the kernel panic, you'll see a message about the kernel being "tainted" or not. This means tainted with non-free code...

Answer 2

Your question reads at first like an advertising... That said:

1) Which party hold the responsibility to support/resolve the bugs of Linux kernel when EOS is in production?

If this is a vanilla kernel, you can submit bug report to the LKML for sure. NONE has a responsibility to do fix your bugs. Someone may help. This is a gift, not an obligation. If this is a patched kernel with proprietary LKMs it will likely be dismissed and ignored politely or with fracas by the kernel maintainers. The commercial distributor may offer most likely a support contract and may accept such responsibility otherwise.

Short of this, none but YOU has the responsibility to support free and open source you use. Anything else is a courtesy and a gift from the project authors, maintainers and any willing good soul.

2) Does Arista (vendor) suppose to distribute EOS (commercial product) with source code or as closed source?

A commercial distributor of a Linux kernel and distro that contains GPL-licensed code has obligations to provide the corresponding source code to the parties they redistribute binaries to. I am sure that this vendor does this alright like the vast majority of Linux distributors do and like the vast majority of device vendors that bundle a kernel do as well. If they sell this distribution as they are entitled to do so, their redistribution of source code can be limited to their paying customers that received the binaries. The same applies if they sell devices that contain a Linux kernel. They have no other general obligation. And certainly no obligation beyond the recipients of the binaries, such as making source code available to the general public.

3) What is the significance to mention MODULE_LICENSE("GPL") in every Linux kernel module?

This tag informs the kernel (and in particular through the use of the insmod and other kernel module loading utilities) that this module declares itself as GPL-licensed and in return the kernel grants access to this module to kernel symbols exported as GPL-only and to kernel internals. As such it could interpreted either as weak indication of licensing and not much more that than. And as an indication that this module may depend on and require access to GPL-symbols exported by the kernel.